What is UFO?

The format was developed and is maintained by Erik van Blokland, Tal Leming, and Just van Rossum. The official UFO Specification is available at unifiedfontobject.org.

Because UFO is application neutral, several typeface design and font production tools use it natively; these are referred to as UFO Tools. Other applications can import from and export to UFO, using it only as a secondary format.

Advantages of UFO

UFO is XML

The format is standards-based and future proof, and easy to read and write using existing XML code libraries.

Open and documented format

The UFO Specification is publicly available, and its development process is open. Multiple tool makers and foundries contribute to it.

Each glyph in a file

The UFO format is modular, with each glyph stored in a separate .glif file. This makes it easy to access and track versions.

UFO3

Most of these features were already supported in previous versions of RoboFont, but as custom additions to the UFO2 format.

UFO3 improves interoperability between different editing tools, and enables new workflows based on layers. (The previous implementation of layers in UFO2 had some limitations: for example, all layers of a glyph had to share the same width.)

UFO continues to be actively developed. The UFO Roadmap includes plans for UFO3 updates, and ideas for UFO4.